Water heater thermostat wrench



FIG. 1 is a top front perspective view of a water heater thermostat wrench showing my new design;

FIG. 2 is a top plan view thereof, the bottom plan view being unornamented;

FIG. 3 is a front elevation view thereof, the rear elevation view being unornamented; and,

FIG. 4 is a right side elevation view thereof, the left side elevation view being unornamented. 

The ornamental design for a water heater thermostat wrench, as shown and described. 